LAC 43:XIII.1709. Repair of Steel Pipe [49 CFR 192.309]

A. Each imperfection or damage that impairs the serviceability of a length of steel pipe must be repaired or removed. If a repair is made by grinding, the remaining wall thickness must at least be equal to either: [49 CFR 192.309(a)] 1. the minimum thickness required by the tolerances in the specification to which the pipe was manufactured; or [49 CFR 192.309(a)(1)] 2. the nominal wall thickness required for the design pressure of the pipeline. [49 CFR 192.309(a)(2)] B. Each of the following dents must be removed from steel pipe to be operated at a pressure that produces a hoop stress of 20 percent, or more, of SMYS unless the dent is repaired by a method that reliable engineering tests and analyses show can permanently restore the serviceability of the pipe: [49 CFR 192.309(b)] 1. a dent that contains a stress concentrator such as a scratch, gouge, groove, or arc burn; [49 CFR 192.309(b)(1)] 2. a dent that affects the longitudinal weld or a circumferential weld; [49 CFR 192.309(b)(2)] 3. in pipe to be operated at a pressure that produces a hoop stress of 40 percent or more of SMYS, a dent that has a depth of: [49 CFR 192.309(b)(3)] a. more than 1/4 inch (6.4 millimeters) in pipe 12 3/4 inches (324 millimeters) or less in outer diameter; or [49 CFR 192.309(b)(3)(i)] b. more than 2 percent of the nominal pipe diameter in pipe over 12 3/4 inches (324 millimeters) in outer diameter. [49 CFR 192.309(b)(3)(ii)] C. For the purpose of this Section a "dent" is a depression that produces a gross disturbance in the curvature of the pipe wall without reducing the pipe-wall thickness. The depth of a dent is measured as the gap between the lowest point of the dent and a prolongation of the original contour of the pipe. D. Each arc burn on steel pipe to be operated at a pressure that produces a hoop stress of 40 percent, or more, of SMYS must be repaired or removed. If a repair is made by grinding, the arc burn must be completely removed and the remaining wall thickness must be at least equal to either: [49 CFR 192.309(c)] 1. the minimum wall thickness required by the tolerances in the specification to which the pipe was manufactured; or [49 CFR 192.309(c)(1)] 2. the nominal wall thickness required for the design pressure of the pipeline. [49 CFR 192.309(c)(2)] E. A gouge, groove, arc burn, or dent may not be repaired by insert patching or by pounding out. [49 CFR 192.309(d)] F. Each gouge, groove, arc burn, or dent that is removed from a length of pipe must be removed by cutting out the damaged portion as a cylinder. [49 CFR 192.309(e)]